What is a varicocele?

A varicocele (pronounced vari-co-seal and sometimes spelled varicocoele) is a network of swollen veins in your scrotum, near your testicle. Some people say it feels like a 'bag of worms'. It usually occurs on the left side of the scrotum but it can also occur on both sides. It’s uncommon to have a varicocele only on the right side.

A varicocele can develop around puberty. It is more common as you get older.

What causes a varicocele?

A varicocele is caused by a problem in the veins that drain blood from the testicles. Veins contain valves that keep blood flowing towards your heart. If a valve is not working properly, blood can leak backwards and pool in the vein. Eventually, the veins become larger than normal.

You are more likely to develop a varicocele if it runs in your family, or if you have varicose veins in your legs.

Rarely, a kidney tumour might cause a varicocele to develop suddenly, and then it is usually painful.

You might discover you have a varicocele during regular testicular self-examination. Learn how to do a testicular self-examination.

What symptoms might I have?

If you have a varicocele there will probably be a lump in your scrotum, which is easier to notice when you’re standing up. If the varicocele is small, you might only notice it if you cough or strain (as though you’re trying to push out a bowel motion).

Most people don't feel any pain from a varicocele. Some people find it can be painful or uncomfortable, especially after exercise, standing for a long time, or at the end of the day. You might feel a dull ache or 'dragging' sensation, or your testicle might feel heavy. It usually feels better if you lie down.

A varicocele is usually harmless, but sometimes it can cause your testicle to shrink. It can also lead to infertility if it interferes with the production of sperm by your testes.

How will my varicocele be diagnosed?

Your doctor will usually be able to diagnose a varicocele by examining your testicles.

If the lump is small or difficult to feel, you might need an ultrasound of your scrotum to see it better.

You might find out you have a varicocele if you are seeing a doctor about fertility problems.

When should I see my doctor?

If you have pain or notice a lump in your scrotum, it’s important to talk to your doctor about your symptoms. Your doctor will be able to check what’s causing the lump and whether it could be something more serious, such as testicular cancer.

If you have a varicocele and you're worried about the possibility of infertility, it’s a good idea to discuss it with your partner and your doctor.

What treatment can I have for a varicocele?

If you have no symptoms and no fertility problems, you might not need any treatment.

If your varicocele is painful, if it is making one testicle smaller than the other, or if you are suffering from fertility problems, your doctor might suggest treatment.

A varicocele is treated by surgery. There are two options.

One option is an operation to tie the veins. This is done by making a small cut in your groin under general anaesthetic. It can also be done through keyhole surgery.

The other option is called embolisation. This is done by a radiologist. It uses tiny metal coils to block the veins that are causing the problem. They are inserted through a tiny cut made in the skin, often in the groin. This is done under local anaesthetic and sedation. Recovery is usually quick.

Sometimes, treating a varicocele can improve fertility.

Resources and support

Read more about varicoceles at the Healthy Male website.

On this site, you can also learn more about how to keep your testicles healthy and do a testicular self-examination.